The present invention generally related to a storage system and a data migration method and, for instance, can be suitably applied to an archive system that stores data for a long period of time.
Recently, in the field of storage systems, the concept of data lifecycle management (DLCM) is being proposed. This concept is an attempt to effectively store and manage data as a result of taking note of the fact that the value of data changes with the lapse of time.
For example, since the act of storing data with a reduced value in an expensive storage apparatus referred to as a “1st tier” is a waste of storage resources, information with a reduced value is archived in an inexpensive storage apparatus referred to as a “2nd tier” which is inferior to the 1st tier in terms of reliability, response and durability as a storage device.
Among the data to be archived, there are data that must be stored for a given period of time under laws or according to internal regulations and the like. Depending on the type of data, there are certain data that need to be stored for a period of several years to several ten years (even longer in some cases).
In the foregoing case, since a storage apparatus has a service life, if the legal storage period of the archived data extends for a long period of time, the process of migrating data from an old, existing storage apparatus (hereinafter referred to as the “existing storage apparatus”) to a new storage apparatus (hereinafter referred to as the “new storage apparatus”) will become necessary during the storage period of the data. Data migration between storage apparatuses is also conducted daily in storage systems other than archive systems.
In relation to data migration, Japanese Patent Laid-Open Publication No. 2007-48323 discloses a virtualization controller that controls the data migration processing between a plurality of storage apparatuses, and Japanese Patent Laid-Open Publication No. 2006-72981 discloses technology of protecting data migrated from a primary storage system to an external storage system concerning DLCM.